My roommate and I moved in together in October, my 4 year old cat came with me (she is declawed and very gentle). About a month later my roommate's 9 year old cat moved in as well (he is also declawed and normally gentle). The older cat is also larger and has begun bullying the younger cat. He chases her into corners and then smacks her repeatedly until she is rescued by a human. She usually urinates and/or defecates once cornered and cowering. At first they seemed to at least be able to share a room but now the older cat has beaten the younger into submission: she stays on top of a high stool in th kitchen (where her food is) for most of the day and night, will only come off if carried into another room. She has begun to urinate and defecate in the kitchen and bathroom on rugs rather than in the litter box (which was originally hers). I believe it is because she has become too frightened to leave the kitchen once in it or to run past the larger cat to get to the litter box. I have placed a second litter box in my room for her to use, but I have to actually carry her into the room and close the door before she will roam around. She hides in closets and has a new nervous habit of looking behind her every few seconds, waiting for an attack. We have tried water spray bottles but the only effective means thus far has been to put one or the other in a closed room for a time period. We have tried separating their food to avoid competition. My cat is miserable and I want to figure out a way to keep the other cat from attacking all of the time. She was adopted from an animal rescue organization so I am not sure if her behavior stems from previous treatment. I am heartsick that she doesn't go anywhere, sit in my lap, take naps in the sun, purr, slobber on my shirt, or do anything that she used to do anymore. What can we do to help our cats co-exist more peacefully? Please please please help! :sad:

Oh your poor kitty!! The big changes that have happened have probably affected both cats, and they are reacting in different ways. Did you do proper introductions, or just let both cats loose in the house immediately?

The male cat is probably stressed from the move and is redirecting his stress unto your cat. Your cat is avoiding the litterbox to communicated HER stress.

Spraying him with water is probably making the situation worse, as it's increasing his stress.

For right now, rotate them, so one is locked in a bedroom and the other loose in the house. DO NOT ever leave them out alone together. Your cat could become very ill from this harassment. Do not allow the male to bully her at all.

Get some Rescue Remedy and start giving it to both cats. Give it a few days to work, then reintroduce the cats and watch closely. If there is any bullying, lock up the male and try again in a few days.

Give them catnip and use toys to distract and help them use up energy.

We are trying out the rotation and my cat is doing a lot better, but they are still kept separate at all times. I am not sure for how long we should continue before trying them out togther (under supervision, of course) because I don't want to re-traumatize my cat but I feel like they are going to have to get used to each other eventually. I really appreciate the advice, my cat is much, much happier which naturally makes me much, much happier! It is nice to see her playing and roaming around the house again (when it's her turn). It took a few days but she seems more confident as she moves around the house. Thank you all for the support - I appreciate everyone's interest and willingness to help out.

Glad to hear things are improving! Cats handle stress very very poorly, and what you are doing now is minimizing it. Also, now the scent of both cats will be all over the house, which will make the re-introduction easier.